Determining aqueous deuterium detection limits via infrared spectroscopy to understand its capabilities for real-time monitoring of tritiated water

• Real-time monitoring of deuterium in water has been shown via an industrial FTIR. • FTIR is fast, produces no secondary waste and has a large existing supplier base. • Detection limits for a benchtop and industrialised FTIR system were determined. • FTIR is a viable means of quantifying high activity tritiated water non-destructively. Tritiated water will be present in many demonstrator class fusion devices in a wide array of locations and concentrations. Accurate and fast measurement will be a key requirement to ensure suitable process monitoring, safety assurance and tritium tracking is in place. This work quantifies the deuterium detection limits achievable using a benchtop transmission Fourier transform infrared (FTIR) instrument and an industrialised attenuated total reflectance (ATR)-FTIR instrument to understand the capabilities of these techniques for real-time monitoring of aqueous tritium. Deuterium limits of detection of 4.62 × 10 -5 mol mL -1 and 1.07 × 10 -3 mol mL -1 were demonstrated with measurement times of 10s for the transmission FTIR and ATR-FTIR, respectively. These instruments are considered viable for the measurement of high concentration tritiated water and have many potential benefits associated with their deployment.